Where do I fit in?

Last night I went to go see Listen to Your Mother at the Alberta Rose Theater. The audience was almost the exact reverse of what I see at tech events. The room was filled with women with a few token men scattered throughout the audience. I can’t remember the last time I was in a room with that particular gender configuration, which says a lot about where I choose to spend my time. But I digress.
While I was waiting for the show to begin, it became obvious (although not at all surprising) that I was surrounded by mothers. I was there alone and didn’t know the WiFi password, so I mostly just sat there and eavesdropped. The chatter in my immediate vicinity was primarily women either expressing relief at getting a night out with  friend or sharing an anecdote about their child(ren).
The show was comprised of 13 mothers telling stories of motherhood. All but one spoke about their own experience as mothers. The exception was a woman telling her story about being the daughter of an abused mother.
Personally, I felt uncomfortable during the readings.  Like I was intruding on someone else’s private space.  The audience was vocal with their recognition of the joys and challenges of motherhood while I sat there mute.
What I am feeling is not at all related to my feelings of competence around parenthood. I feel like I am as prepared for that as anyone can possibly be. My issue is that I feel like a poseur around parents. Which is particularly unnerving because I felt perfectly comfortable with my friends who are parents before we initiated the adoption process.
There seems to be something about the process of becoming a parent that has me feeling like an “other.” Like I am no longer simply a woman without children. I am now a woman embarking on a journey towards parenthood.  And that has left me feeling awkward and uncertain about where I fit in.
Let me be abundantly clear that my friends who are parents have embraced me during this process.  At no point have I felt lesser than or excluded by any of them. And I am 100% confident that they will welcome my child into our community with open arms. The issue lies entirely with me.  I am the one feeling like a fraud.
 
All of the adoption books I have read have mentioned the importance of support groups during the adoption process. And to be completely frank, I was confident that I would not need one. They were obviously talking about other people. But I am now beginning to understand the wisdom of finding a support group to help me (and us) through this transitional period. It makes me genuinely curious to know if other prospective parents are feeling the way I am.